After upgrading from Parallels Desktop 15.1.5 to 17.1.4, I noticed that external drives can no longer be ejected when accessed in the VM. macOS then displays a warning when ejecting that there are open references to the drive. A downgrade to 17.0.1 did not solve the problem. Only with the installation of 16.5.1 the problem disappeared. So the bug seems to affect all 17.x versions. To reproduce: 1) Connect an external drive and access the drive via the mapped drive letter in the VM 2) Eject the external drive in macOS 3) macOS shows a warning that the drive cannot be ejected 4) sudo lsof /Volumes/Backup ('Backup' stands for volume name) shows that prl_vm_ap prevents the ejection
